Chemical Changes in steel surfaces During Extreme Pressure Lubrication

Analysis may aid in explaining the mechanisms by which gear lubricants, particularly EP oils, function. Which  it is  generally  accepted  that  iron sulfides, chlorides and  phosphates are  possible reaction products  of  EP additives  under extreme operating conditions, this  may not  be the  complete explanation. Godfrey^5 considered that there was a lack of understanding of the above actions. Consequently, EP films and  fragments  were  obtained  and  analyzed  by : electron  diffraction, X-ray diffraction, emission  spectrograph, proton  scattering, chemical spot tests, and  volumetric  analysis. For one wishing to study the chemical mechanisms of extreme pressure lubrication this article should provide suggestions as to analysis. Suggestions have also been made that changes in EP additives while in service may be measured by infra-red spectroscopic technique.